The presence of light hydrocarbons in crude oil contributes to the volatility of the oil. The presence of substantial amounts of propane, butanes, and lighter hydrocarbons in the crude oil can cause an increase in the vapor pressure within the container in which the crude oil is handled, stored, or transported, creating a risk for explosion during handling, storage, and transport of the crude oil. A number of rail car accidents have recently occurred, which resulted in fires and casualties due to explosions of containers carrying volatile crude oil. The risk of explosion due to volatility increases when crude oil is produced and/or stored in a cold climate and subsequently shipped to a warmer climate, as volatility of the crude oil increases with an increase in temperature. This issue is particularly prevalent for crude oil produced in the Bakken Shale formation, where the crude oil is especially volatile.
Due to the recent disasters and high volatility of the crude oil in the Bakken Shale formation, in April 2015, North Dakota implemented regulations requiring the Reid Vapor Pressure (RVP) of transported crude oil to be no greater than 13.7 psia or 1 psia less than the vapor pressure of stabilized crude oil as defined in the latest version of ANSI/API RP3000, whichever is lower. One common attempt at reducing the volatility of the crude oil to comply with regulations has been to use a heater-treater. However, heater-treaters are not designed to run at temperatures necessary to stabilize the crude oil. While it is possible to run heater-treaters at high enough temperatures to reduce the volatility of the crude, at such temperatures, the fire tube of the heater-treater is highly susceptible to coking, and eventually fails as a result.